Technical Field
The embodiments herein generally relate to a signal processing and estimation system and techniques and particularly relates to a system for measuring a Direction of Arrival (DOA) of an incident signal. The embodiments herein more particularly relates to a system and method for estimating the direction of arrival (DOA) of a wireless signal and localizing a source of wireless signal using displaced circular arrays of antennas.
Description of the Related Art
Direction of Arrival (DOA) is considered as the most accurate and robust method in localization. A DOA technique can obtain an angle data using the radio array methods. The DOA technique involves analyzing a time or a phase difference between the signals at different array elements that are arranged at known locations with respect to the centre element. Generally, the correlated signals are difficult to be processed and cannot be resolved with the traditional DOA techniques, but can be resolved with some computational expensive algorithms such as spatial smoothing.
One of the existing methods of measuring DOA is Uniform Circular Array (UCA) technique. In a Uniform Circular Array (UCA) configuration, the elements are placed on a circular ring. The circular array comprises a predefined number of elements that are equally spaced on a plane along the ring of a set radius. The steering vector of the circular array includes azimuth angles. This method is evolved based on a standard circular array configuration and processing. The Uniform Circular Array (UCA) method is not able to resolve the signal coherency problem and has high computational complexity. The accuracy and resolution of the UCA method is also less compared to Uniform Circular Displaced Sensor Array (UC-DSA).
Another method of measuring the DOA is a Uniform Linear Displaced Sensor Array (UL-DSA) technique. The UL-DSA comprises a Displaced Sensor Array (DSA) configuration. The DSA consists of two parallel Uniform Linear Arrays (ULAs) displaced by a horizontal distance and a vertical separation. Each of the two parallel ULAs consists of linear equally spaced omni-directional antennas with a fixed inter-element spacing. It is assumed that the DSA configuration receives the narrowband source signals from the incidence directions. Though the UL-DSA configuration provides two parallel equally spaced omni-directional antennas with a fixed distance between elements, the UL-DSA configuration cannot separate the correlated signals, since the signals coincide in phase at the two set of arrays. In this condition, the UL-DSA is not able to solve the coherence problem of the incident signals.
Hence, there is a need for a system and method with improved design to evaluate and estimate a Direction of Arrival (DOA) of an incident signal. Further, there is a need for a system and method to solve the coherency issues with an incident signal. Furthermore, there is a need for a method to provide a less computational and a highly accurate solution for measuring the DOA.
The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.